David Blair became Chief Foreign Correspondent of the Daily Telegraph in November 2011. He previously worked for the paper as Diplomatic Editor, Africa Correspondent and Middle East Correspondent.

Shadowy war of sabotage against Iran's nuclear facilities

Every so often, the veil is lifted on the shadowy war of sabotage being waged against Iran’s nuclear facilities. Another of those moments arrived yesterday when Fereydoun Abbasi, the head of Iran’s Atomic Energy Organisation, disclosed that his country’s most sensitive nuclear facility was targeted last month.

As so often, Iran’s account of this incident raises more questions than answers. Fordow is the most sensitive nuclear plant that Iran possesses – this is the facility dug into a mountainside beneath perhaps 260ft of rock and earth. As such, it seems pretty extraordinary that it would lack a power supply of its own and rely on a normal grid connection to Qom.

Then again, the power cut seems to have done no lasting damage. We know that because the IAEA visited Fordow on August 18, the day after the explosion, and released their latest report on Iran’s nuclear programme on August 30. This makes no mention of any damage in Fordow. If the centrifuges spinning inside the plant had been shut down by a sudden loss of electricity, they would have torn themselves to pieces as they decelerated. So perhaps Fordow has a back-up system that would allow its centrifuges to survive a power cut. That would certainly make sense. But why, then, did the saboteurs bother to blow up the power cable at all if this would inflict no damage?

Abbasi used the incident to discredit the IAEA, asking whether its inspectors might have been behind the explosion on the grounds that they happened to visit Fordow a day later. His theory seems to be that the IAEA experts actually arrived on a damage assessment mission. If so, they seem to have found no damage and the incident had no impact. Or maybe the centrifuges were harmed, but the inspectors somehow failed to notice.

It will be interesting to see whether the next IAEA report, due at the end of November, makes any mention of this mysterious episode.